Like many Japanese Americans trying to fit in at school, Katsumi changed his name: he became John. He graduated from Stockton High School in 1933. The following year after studying the Japanese language, he enrolled at Waseda University in Tokyo and was accepted into the Jikei Medical School where he studied medicine taught in two languages – Japanese and German. After graduation, he worked at a hospital in Tokyo. He recalled when WWII began and American airplanes bombed the Tokyo area. He lost some of his personal belongings, including his high school yearbook. Fortunately, he was not injured. 

He was finally able to return to the USA in 1949 after spending 16 years in Japan. He joined his parents and other family members in Denver after the internment camps were closed. After a brief stay in Denver, he and his parents returned to their home on W. Washington St. in Stockton. He completed his medical residency at Sacramento County Hospital and in the early 1950s, opened his medical practice on S. Madison St. next to the family home. With his bilingual English and Japanese language fluency, he served the Japanese community for many years as a physician and surgeon delivering babies, performing minor surgery, everything today’s primary care physician would do, and even making house calls. He ran his practice by himself – answering the phone, handling insurance claims, and treating patients. Many of his patients were farmworkers who brought crates of fresh produce from the region, including asparagus, cherries, grapes, and other local crops. 

In the early to mid 1950s, his parents’ health had declined significantly. Hae had diabetes and Juichi suffered several strokes. John managed to take care of his patients and his parents. Hae passed away on September 24, 1956 and Juichi passed away less than five months later on February 17, 1957.